Retractable hard formation bit



Jan. 4,1944. 5 w sEwE 2,338,670

RETRACTABLE HARD FORMATION BIT Filed March 26, 1942 2 Sheets-Sheet 1 i ,llmi

l6- HM 2 O L I3 5 I i I4 !4 FIG M7 6 hwz. WJM INVENTORJ ATTORNEY Patented Jan. 4, 1944 UNITED STATE RETRACTABLE HARD FORMATION BIT Benjamin W. Sewell, Tulsa, Okla., assignor to Standard Oil Development Company, a corporation of Delaware Application March 26, 1942, Serial No. 436,293

4 Claims (Cl. 25575) The present invention is directed to a wire line retractable drilling bit.

An object of the present invention is to devise a drill bit which may be lowered and retrieved through the bore of the drill pipe.

A further object of the present invention is to devise a bit which may be lowered and retrieved through the bore of the drill pipe and which is provided with cutters adapted for drilling hard formations.

Other objects and advantages of the present invention may be seen from a reading of the following description taken in conjunction with the drawings in which Fig. l is an elevation, partly in section, of a bit embodying the present invention with the cutters expanded for drilling;

Fig. 2 is an elevation, partly in section, of the device of Fig. 1 with the cutters of the bit retracted so that the device may be moved along y the bore of the drill pipe;

Fig. 3 is a fragmentary view, partly in section, of the lower end of the device in the condition shown in Fig. 2, but at an angle of 90 to the view of Fig. 2;

Figs. 4 and 5 are fragmentary views illustrating different arrangements for locking the drill bit to the drill pipe; and

Fig. 6 is a view taken along lin Figure 5.

Referring specifically to the drawings and first to the device disclosed in Figs. 1, 2 and 3, a body I I having a medial portion of a generally tubular shape is shown with its upper end extending into the lower portion of a string of drill pipe in. The lower end of body ii is biiurcated'to form extensions I2. Secured to bifurcated portion I! by pivots [3 are arms' l4 carrying cutters l5. It will be seen that the arms M are so attached that they may hang in a substantially vertical posi--' tion as illustrated in Fig.2, or else may be extended outwardly at an angle as shown in Fig. 1. When arms I4 hang down in a vertical position, cutters l5 are adiacent one another, and the device may be passed through a suitable drill stem. When the cutters ii are expanded outwardly, they define a circle of greater diameter than the drill stem, and accordingly will produce a bore hole of sutiicient diameter to allow normal drilling operations.

Arranged immediately above bifurcated portions I! are lugs i8, and at substantial distance above them isgshoulder l1. Shoulder ll and lugs I have substantially the same outside diameter.

e VIVI of downward and upward movements restricted by lugs l6 and shoulder ll, respectively, is sleeve ll having its upper end of tubular form, .an outside diameter corresponding to that of shoulder I1 and provided with two downward extensions [9 arranged to slide between lugs It. The lower end vof extensions iii are joined together by wedge-shaped member 20 and arranged below member 20 are cone-shaped rock cutters 2 I, each cutter being secured to one of the extensions l9.

Extending down through body H is longitudinal passage 22 which serves to conduct drilling fluid through the drill bit. Arms M are provided with mud passages (not shown) communicating with passage 22 and extending adjacent cutters IE to carry drilling fluid to these cutters. In like manner, member 20 is provided with passage 24 to convey drilling fluid to the coneshaped rock bits 2 i The general operation of the device or the present invention will now be ,explained. The drill bit consists generally of two units, one unit carrying the two rock bits I! and the other unit carrying the two rock bits 2|. These two units are slidingly interrelated. When the device is to -be moved along the bore 0! the, drill pipe, the force of gravity pulls the unit carrying rock bits 2| downwardly and allows the rock bits [5 to swing inwardly, thereby permitting the passage 0 01 the tool through the bore 01 the pipe.

When the device reaches the bottom or the bore hole. conical cutters 2| strike the bottom first, and member II will accordingly slide through collar [8, carrying cutters l5 downwardly. Wedgeshaped member 20 spreads arms [5 so that the cutters l5 are expanded outwardly and the device is in position to cut a'hole of larger diameter than the maximum diameter of the drill pipe.

It is essential that means be provided to lock the device of the present invention to the drill collar, so that rotation of the string of drill pipe will correspondingly rotate it. A suitable mean: for locking the device to thedrill stem is illustrated in Fig. 4 and another means is illustrated in Fig.5.

In the locking means disclosed in Fig. 4, slips 33 have their lower ends secured to body H by pivots 34. Arranged to cooperate with body H is an upper member 36 or a general cylindrical shape. The lower portion of member 36 fits around the upper portion of body H so that the two elements can move longitudinally with respect to each other. The upper end of body It is provided with a circular outwardly projecting Blidingly arranged on body II with its maximum ledge 35. Inwardly extending ledge ll is formed in the lower portion of body 36 to cooperate with projection 35 to limit the relative movement of these two bodies. The lower portion of body 35 is shaped to form an inverted truncated cone 38.

When portion 38 comes in contact with slips 33,

which may be used to retract the device by means of a wire line. Packing rings 40 are provided on body 36 to seal the space between the body and the drill stem against drilling fluid.

It will be apparent that the arrangement above described is provided with cutting means for drilling a bore hole and with locking means for locking thercutters so that they will rotate upon rotation-of the drill string. In order to concentrate Weight of the lower end of drill pipe a drill collar may be lowered through the drill stem until its lower end rests on the upper portion of body 36. Such a drill collar is designated by numeral 4|. It will be apparent that as many drill collars as desired may be used with each succeeding drill collar resting upon the preceding collar.

In Figs. 5 and 6 is illustrated another means suitable for locking the device for rotation with the drill collar. This locking means may be sub-. stituted for that shown in Fig. 4. In the embodiment of Figs. 5 and 6 a pluralit of teethed eccentrics 26 are mounted on longitudinally extending shafts 21 secured to body ll. When the assembly is in position in the lower end of the drill stem, and the drill pipe is rotated in a clockwise direction, the frictional contact between the drill pipe, and the eccentrics will cause the teeth to bite into the drill pipe, whereby the rotary motion will be transmitted through the body to the bits. A packer 29 is provided to prevent the loss of drilling fluid between body I l and drill pipe Hi. It will be evident that when it is desired to remove the assembly from the drill pipe, the direction of rotation of the pipe may be reversed, releasing the eccentrics from the pipe.

Thereupon, a conventional overshot (not shown) may be lowered on a wire line until it engages spear head 3 I. Tension placed upon the wire line will then cause the withdrawal of the device upwardly through the drill stem.

While I have disclosed specific embodiments of the present invention, it will be obvious to the skilled worker that various changes may be made without departing from the scope of the invention. For example, while I have disclosed specific shapes of rock bits, it will be apparent that various other types of cutters may be substituted for those herein disclosed. Moreover, while I have disclosed specific means of locking the device to the drill stem, various other locking means at present known to the drilling and production art may be so employed. It is accordingly my intention not to be bound by the specific embodiments herein disclosed, but only in accordance with the hereto appended claims.

Iclaim:

l. A wire line retractable hard formation drilling bit comprising, in combination, a body, outters suitable for drilling hard formations connected to said body, a sleeve slidably arranged on said body, cutters carried by said sleeve and means carried by said sleeve arranged to expand said first mentioned cutters outwardly when in one position and to allow said first mentioned cutters to retract when in a second position.

2.,A wire line retractable bit comprising, in combination, an elongated body, arms having one end secured to said body and the other end adapted to expand outwardly, a sleeve arranged on said body for slidable movement, cutters carried by said sleeve, and a wedge-shaped member carried by said sleeve arranged to expand the unsecured ends of said arms outwardly when in one position, and to allow said arms to retract inwardly when in another position.

3. A wire line retractable drilling bit comprising, in combination, a tubular member having its lower end bifurcated, an arm pivoted to eachbifurcated portion, a bit carried by each arm, a sleeve slidably' arranged on said tubular member, outwardly extending members secured to said tubular portion to define the upper and lower limits of movement of said sleeve, downwardly extending members secured to said sleeve, rock bits carried by each downwardly extending member, and a member secured to said downwardly extending members arranged to expand said arms outwardly when said sleeve is in its upper position and to allow said arms to swing inwardly when the sleeve is in its lowermost position.

4. A wire line retractable drilling bit adapted for longitudinal movement in a drill pipe comprising,'in combination, an elongated body having a central passage extending therethrough, a bifurcated lower end portion and an intermediate portion of lesser cross section than said end portion, an arm pivoted to each bifurcated portion of said lower end portion, a bit carried by each arm, a sleeve slidably mounted on said intermediate section, downwardly extending arms rigidly secured to said sleeve, bits carried by the rigidly secured arms. and a wedge shaped member carried by said rigidly secured arms and arranged to 

